i'm bob abernethy. you can follow us on twitter and facebook and watch us anytime on the pbs app for iphones and ipads. there's always much more on our website as well. you can comment on all our stories and share them. audio and video podcasts are also available. join us at pbs.org. as we leave you, music from the choir of trinity church wall street, in new york. ♪ additional funding also provided by mutual of america. designing customized individual and group retirement products. that's why we're your retirement company. the jane henson foundation and the corporation for public broadcasting.